DAMAGE MECHANICS

Damage mechanics of composite materials is concerned with the various damage mechanisms, their evolution under thermomechanical loading, and their effect on the elastic , failure , and fatigue behavior of a composite structure. Damage mechanics analysis comprises damage characterization, damage evolution, and their relationship to stiffness and strength degradation of the material, leading ultimately to life prediction
models.

A characteristic damage mechanism in crossply laminates under tensile loading is transverse microcracking

Master curve for applied stress vs crack density in
crossply laminates at different temperatures

Damage mechanisms and evolution in crossply laminate under
tensile fatigue loading

Stiffness degradation of a composite laminate under fatigue as a function of
normalized logarithmic lifetime for various stress levels with three characteristic stages of damage development.

Master curve for normalized damage under fatigue loading in crossply laminates at different temperatures

Cyclic stress and residual strength of composite laminate under fatigue